Phase separator



Dec. 20, 1966 P. cHARLE ET AL PHASE SEPARATOR Filed Jan. 12, 1965 UnitedStates Patent 2 Claims. CI. 62-50) The present invention relates to aphase separator for liquefied gas circulation systems.

A particular object of the invention is to make it possible incirculation systems for conveying liquefied gases at very lowtemperatures to remove any quantities of gas which are gasified duringtransfer from place to place and to the points of utilization with aminimum pressure loss while at the same time preventing heating of theliquefied gas considered.

This invention relates to a phase separator for a liquetied gascirculation system comprising a separating chamber which is provided atthe bottom portion thereof with a conduit for the admission of liquidand a conduit for the discharge of liquid and at the top portion thereofwith gas-removing means fitted with a shutting-01f device, and means forcontrolling said gas-removing means in dependence on the depth of liquidwithin the separating chamber, characterized in that said control meanscomprise a manometric capsule consisting of a first chamber connected tothe bottom portion of the separating chamber by means of a pipe in whichthe liquefied gas vaporizes and a second chamber connected to the topportion of the separating chamber, said two chambers being separatedfrom each other by a deformable diaphragm.

There will now be described below one example of construction which ischosen by way of indication and not in any sense by way of limitation.This example relates to a phase separator which is designed to be placedbetween two sections of a vacuum insulation pipe of the type usuallyemployed for the purpose of conveying liquefied gases at very lowtemperature as has been described in particular in French Patent No.1,322,181 of Jan. 23, 1962 in respect of Pipe-line for conveyingliquefied gas.

The description which is given hereunder relates to FIG. 1 of theaccompanying drawings, which represents a diagrammatic view in verticalcross-section of the apparatus according to the invention.

As shown in this figure, the separator described consists of avertically-disposed separating chamber 1 of cylindrical shape, at thebottom portion of which is provided a conduit 2 for the admission of theliquid-gas mixture and a conduit 3 for the discharge of liquid phase,which is located diametrically opposite to said admission conduit and atthe top portion of which is provided an opening 4 for the removal of thegaseous phase. A plane vertical partition wall 5 which is interposedbetween the inlet conduit 2 and outlet conduit 3 facilitates theseparation of the two phases.

The separating chamber 1 is arranged coaxially in the interior of avessel 6 which is also cylindrical and which is provided with lateralextensions 7 and 8 around the conduits 2 and 3. The admission conduit 2together with its outer sleeve which is formed by the extension 7 of theseparating chamber has a shape which is identical with that of onefemale extremity of the pipe-line sections in which the separator isintended to be placed. Conversely, the conduit 3 and the extension 8 ofthe outer vessel constitute a male extremity, The inlet and ice outletconduits 2 and 3 are fitted with contraction bellows 9 and 10respectively, in the same manner as the pipe-lines for conveyingliquefied gas. 7

A valve 11 serves to create a vacuum within the space which is formedbetween the separating chamber and the outer vessel 6. The vacuum thuscreated can if necessary be maintained by means of a mass 12 ofactivated carbon which is contained in a perforated basket 13. Inaddition, the separating chamber 1 is provided on the external facethereof with a glossy multi-layer coating 14 which is intended toreflect thermal radiation.

The relative centering of the two vessels or chambers is ensured bymeans of a log 15 which is integral with the separating chamber 1 andwhich is adapted to penetrate into a cup 16 forming part of the outervessel 6. The lug 15 and the cup 16 are not usually in contact with eachother when the apparatus is in operation.

The separating chamber 1 is put into communication at the top portionthereof by means of the opening 4 and the conduits 17 and 18 with adifferential pressure valve 19. Said valve is a manometric capsule whichis divided into two chambers 22 and 23 by a flexible diaphragm 21. Theconduit 18 and the discharge conduit 24 open into the bottom chamber 23.Said discharge conduit can be shut 01f by means of a disc valve 25 whichis rigidly fixed to the diaphragm. The top chamber 23 communicates withthe lower extremity of the separating chamber 1 via a pipe 26 of smallcross-sectional area. Finally, the valve is fitted with a calibratingdevice 27 which establishes the valve-closing pressure.

In order to avoid any convection process between liquid phase andgaseous phase within the pipe 26, said pipe is designed in the shape ofa siphon and is surrounded by a copper heating sheath 28 in the vicinityof the outer vessel wall.

As an additional feature, the length of the pipe 26 is sufiicient toensure that the heat transfer between the cold wall'of the separatingchamber 1 and the hot wall of the outer vessel 6 is low in value.

The same applies to that portion of the conduit 17 for the removal ofthe gaseous phase which is located within the vacuum space between theseparating chamber 1 and the outer vessel 6. The conduit 17 additionallyhas a coil-shaped section which is located between the vessel 6 and thevalve 19 and the purpose of which is to heat the gas to a sufficientextent to prevent any condensation at the level of the valve 19.Finally, a safety valve 30 which is fitted in the conduit 17 ensures thesafety of the apparatus in the event of abrupt accidental heating of theliquefied gas which is being processed.

The apparatus according to the invention operates as follows: theliquid-gas emulsion which is admitted through the conduit 2 is separatedinto two phases within the separating chamber 1. The liquid phase flowsthrough the conduit 3 whilst the gaseous phase escapes through theconduit 17. The level of liquid within the separating chamber 1 ismaintained between two limits by the valve 19. The force which isexerted on the diaphragm 21 in the direction of closure of the valve isin fact produced by the hydrostatic pressure which is exerted by thehead of liquid phase contained in the apparatus.

The separator in accordance with the invention accordingly permits thepossibility of effecting the separation of the gaseous phase formedwithin a liquefied gas pipeline under excellent conditions of thermalinsulation and with a minimum pressure loss.

What we claim is:

1. Phase separator for liquified gas circulation systems comprising aseparating chamber, a conduit at the bottom portion of said separatingchamber for the admission of liquid, a conduit for the discharge ofliquid for said separating chamber, a manometric capsule, a firstchamber for said capsule, a pipe in which the liquified gas vaporizesconnecting said first chamber to the bottom portion of said separatingchamber, a second chamber for said capsule, a gas removing conduitconnecting said second chamber to the top portion of said separatingchamber, a gas discharge conduit from said second chamber, a deformablediaphragm separating said two chambers and a valve for discharging gasfrom said second chamber cooperating with said discharge conduit andrigidly fixed to said deformable diaphragm.

2. Phase separator in accordance with claim 1, wherein a vacuumenclosure provides thermal insulation of the separating chamber.

References Cited by the Examiner UNITED STATES PATENTS LLOYD L. KING,Primary Examiner.

1. PHASE SEPARATOR FOR LIQUIFIED GAS CIRCULATION SYSTEMS COMPRISING ASEPARATING CHAMBER, A CONDUIT AT THE BOTTOM PORTION OF SAID SEPARATINGCHAMBER FOR THE ADMISSION OF LIQUID, A CONDUIT FOR THE DISCHARGE OFLIQUID FOR SAID SEPARATING CHAMBER, A MANOMETRIC CAPSULE, A FIRSTCHAMBER FOR SAID CAPSULE, A PIPE IN WHICH THE LIQUIFIED GAS VAPORIZESCONNECTING SAID FIRST CHAMBER TO THE BOTTOM PORTION OF SAID SEPARATINGCHAMBER, A SECOND CHAMBER FOR SAID CAPSULE, A GAS REMOVING CONDUITCONNECTING SAID SECOND CHAMBER TO THE TOP PORTION OF SAID SEPARATINGCHAMBER, A GAS DISCHARGE CONDUIT FROM SAID SECOND CHAMBER, A DEFORMABLEDIAPHRAGM SEPARATING SAID TWO CHAMBERS AND A VALVE FOR DISCHARGING GASFROM SAID SECOND CHAMBER COOPERATING WITH SAID DISCHARGE CONDUIT ANDRIGIDLY FIXED TO SAID DEFORMABLE DIAPHRAGM.